1. Field of the Invention
The present invention relates to a control apparatus for an internal combustion engine, and more particularly to fuel injection ratio setting control in an internal combustion engine provided with a first fuel injection mechanism (in-cylinder injector) for injecting fuel into a cylinder and a second fuel injection mechanism (intake manifold injector) for injecting fuel into an intake manifold and/or an intake port.
2. Description of the Background Art
In an internal combustion engine having both an in-cylinder injector for directly injecting fuel into a combustion chamber of a corresponding cylinder and an intake manifold injector for injecting fuel into an intake port of a corresponding cylinder, a configuration for controlling a fuel injection ratio between the two kinds of injectors in accordance with an operation state during a homogeneous combustion operation is known (e.g., Japanese Patent Laying-Open No. 10-103118; hereinafter, also referred to as “Patent Document 1”). In particular, Patent Document 1 proposes a configuration for preventing fluctuations of air-fuel ratio at the time of switching of the fuel injection ratio between the injectors, taking account of a difference in time required until the fuel injected from the respective injectors is introduced into the cylinder.